The invention relates to an aircraft having at least one high lift system which is arranged at the wing of the aircraft and which comprises at least one drive for converting electrical or hydraulic energy into a speed-controlled rotational movement, wherein the aircraft furthermore has at least one control unit which controls the high lift system.
Typically, an apparatus at a wing of an aircraft is to be understood as a high lift system which serves to increase the lift coefficient of the wing in the take-off and landing phases, whereby the aircraft is already able to fly at low speeds. As a rule, the flap systems and/or the slat system is/are to be understood by this. Conventional high lift systems are directly connected to the electrical and/or hydraulic on-board supply of the aircraft. Power is removed from this on-board supply during the actuation of the high lift system.
A central drive unit positioned in the fuselage converts hydraulic and/or electrical energy into a speed-controlled rotational movement having a corresponding torque. The drive unit is connected to the transmission system located in the wing to forward the torque to actuators. The actuators take up the rotational movement of the transmission shafts and convert it into a movement in translation with which the individual flaps of the high lift system are actuated or are moved in and out. The high lift system has a large number of monitoring sensors which monitor the correct system function and serve as regulation parameters for the electronic control. Safety devices avoid critical system defect functions in the event of a defect. The high lift system is linked to flight control computers which represent the interface between the input commands input in the cockpit and the drive unit to be controlled.
When designing high lift systems, their availability is of particular importance. It is typically insured by the architecture of the power supply and of the high lift systems that on a failure of specific power supply systems the slat system can still be actuated to allow a safe landing of the aircraft (so-called stall protection).
It is also of significance to be able to actuate the flap system since then, the landing can be carried out substantially more easily and with much less risk, in particular with still fully fueled and so heavier aircraft.
The availability of the high lift system substantially depends on the availability of the drives and of the power supply systems connected thereto. The failure probability of a hydraulic power supply system of a passenger aircraft is around 5×10−4/Fh. The failure probability of an electrical power supply system is approximately 1×10−5/Fh.
In the prior art, two drive motors have typically been coupled via a transmission to ensure the drive of the high lift systems. In this respect, both drives are each connected to the power supply systems of the aircraft.
These drive units can generally be built up in accordance with the following different architectures:
In active/active operation, both motors are always operated together, with them cooperating via a so-called speed summing differential transmission.
Alternatively, both motors can also be operated together in an active/active operation and can cooperate with a so-called torque summing.
In active/passive operation, one main motor is normally operated, with another motor being available in the event of a defect.
In this prior art, there is the problem that both motors are always connected to the central power supply of the aircraft.
This degrades the availability and results in a comparatively high weight.
It is already known from DE 10 2012 00 53 46 A to decouple the entire high lift system from the central supply and to operate it centrally or per flap operation by using electrical energy stores.
On the other hand, it is known from US 2009/0302153 A1 to provide batteries or ultracaps for the central supply of the aircraft with energy as electrical buffers for the recovery or for the brief increased consumption of electrical supply.